Surgical lengthening of a single flexor tendon in the hand or finger to treat contracture or restricted motion — reported per tendon.

Verified May 8, 2026 · 6 sources ↓

Medicare: $650.98
Work RVU: 5.82
Global, days: 90
Region: Hand

Drawn from CMSAAPCFindacodeEatonhandAAOS

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 6 cited references ↓

Name each tendon lengthened (e.g., FDS ring finger, FDP small finger) — not just 'flexor tendon'
Specify the surgical technique: Z-plasty, step-cut, intramuscular lengthening, or other named method
Identify laterality (left or right hand) and exact digit(s) treated
Clinical indication supporting tendon lengthening: contracture severity, spasticity etiology, prior failed conservative treatment
Intraoperative findings including degree of contracture and range of motion before and after lengthening
Confirm number of tendons lengthened to support unit count if billing multiple units of 26478

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global 24 Unrelated E/M during global LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 26478 covers open surgical lengthening of a flexor tendon in the hand or finger. The procedure addresses tendons that are pathologically shortened due to spasticity, contracture from prior injury, congenital anomaly, or neurological conditions such as post-stroke spastic hand. The surgeon releases or elongates the tendon — most commonly the flexor digitorum superficialis (FDS) or flexor digitorum profundus (FDP) — to restore functional range of motion and reduce fixed deformity.

This code is reported per tendon. If multiple tendons are lengthened in the same session, bill 26478 for each tendon with modifier 51 appended to the additional units. For example, lengthening FDS and FDP on the same finger in the same sitting would support two units of 26478. When the procedure is performed bilaterally in a single session, modifier 50 applies. The 90-day global period means all routine post-op care, wound checks, and suture removal through day 90 are bundled — unrelated services in that window need modifier 24 or 79.

Documentation must identify the specific tendon by name, the surgical technique used (Z-plasty, step-cut, intramuscular lengthening), the digit and hand (LT/RT), and the clinical indication driving the decision to lengthen rather than release. Operative notes that only state 'flexor tendon lengthened' without naming the tendon are a common audit flag and a frequent driver of payer downcoding or denial.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (5.82) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (19.49) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	5.82
Practice expense RVU	12.54
Malpractice RVU	1.13
Total RVU	19.49
Medicare national rate	$650.98
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$650.98
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 26478 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Operative note names only 'flexor tendon' without specifying FDS vs FDP or the digit — payers downcode or deny for lack of specificity
Multiple units of 26478 billed without modifier 51, triggering a bundling edit that collapses payment to a single unit
Missing or mismatched laterality modifier (LT/RT) when bilateral procedures are performed on the same date
ICD-10 diagnosis code does not clearly support tendon lengthening (e.g., contracture vs. tendon rupture codes are frequently mismatched)
Post-op services billed without modifier 24 or 79 during the 90-day global period, resulting in automatic denial

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01Is 26478 reported per tendon or per digit?

Per tendon. If you lengthen both FDS and FDP on the same finger in the same session, that supports two units of 26478. Append modifier 51 to the additional unit(s).

02What's the difference between 26476 and 26478?

26476 is for lengthening an extensor tendon in the hand or finger. 26478 is for lengthening a flexor tendon. The distinction matters — they are not interchangeable and the ICD-10 diagnosis should align with the affected tendon type.

03How do I bill 26478 when both hands are done in the same operative session?

Use modifier 50 for bilateral procedures billed on a single line, or submit LT and RT on separate lines per payer preference. Confirm which approach your payer requires before submitting — Medicare generally accepts modifier 50 on one line.

04What global period applies and what does it include?

26478 carries a 90-day global period. That covers the surgery, the day-before visit, and all routine post-op care through day 90. Unrelated E/M visits in that window require modifier 24; unrelated procedures require modifier 79.

05Can 26478 and 26476 be billed together on the same date?

Yes, if both a flexor and an extensor tendon are lengthened in the same session and operative documentation supports each procedure distinctly. Append modifier 51 to the lower-valued code and ensure the operative note names each tendon separately.

06What ICD-10 codes typically support 26478?

Common supporting diagnoses include M65.9 (tendon sheath disorders), M66.x (flexor tendon rupture with contracture), M72.0 (palmar contracture), and G82/G83 series for spastic conditions following neurological injury. The diagnosis must reflect shortening or contracture requiring lengthening — not just a tendon injury or laceration.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira Scribe

Mira's AI scribe captures the specific tendon name (FDS vs FDP), digit, laterality, surgical technique, and pre/post lengthening range of motion directly from dictation. That detail prevents the most common denial for 26478 — operative notes vague enough that payers can't confirm a billable tendon-level procedure was performed. When multiple tendons are lengthened, the scribe flags each unit separately so modifier 51 is applied correctly at coding time.

See how Mira captures CPT 26478 documentation